Hair straightener



FIG. 1 is a front perspective view of a hair straightener showing our new design;

FIG. 2 is a side view thereof;

FIG. 3 is a side view of the opposite side of FIG. 2;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a front view thereof; and,

FIG. 7 is a rear view thereof.

The broken lines shown in the drawings illustrate portions of a hair straightener that form no part of the claimed design. 

CLAIM We claim the ornamental design for a hair straightener, as shown and described. 